Unfortunately, at this time treatments for primary glaucoma are limited to managing the disease and alleviating chronic pain. Treatments for secondary glaucoma can involve treating the underlying condition which is causing the glaucoma. Since glaucoma is caused by elevated eye pressure (IOP), treatments typically involve taking steps to try to decrease the ocular pressure. Most treatments are temporary and IOP continues to escalate over time. The anatomically unique nature of dogs means that therapies that have worked for decades in humans have a high rate of failure in dogs after short periods.
Initial Treatments to Control Pressure
Initial interventions for dogs with glaucoma often involve treatment with eyedrops that lower the pressure by either decreasing the production of fluid within the eye (aqueous humor) by the ciliary body or increasing the drainage through the trabecular meshwork (TM).
- Prostaglandin Analogs: These medications work by increasing the outflow of fluid from the eye. They are commonly used as the first line of treatment in dogs with glaucoma. Examples include latanoprost and travoprost.
- Carbonic Anhydrase Inhibitors: These medications decrease the production of fluid inside the eye. They are often used in combination with prostaglandin analogs. Examples include dorzolamide and brinzolamide.
- Beta-blockers: These medications decrease the production of fluid inside the eye. They are often used in combination with prostaglandin analogs or carbonic anhydrase inhibitors. Examples include timolol and betaxolol.
- Alpha-2 Agonists: These medications work by reducing the production of fluid and increasing the outflow of fluid from the eye. Examples include brimonidine.
- Miotics: These medications increase the outflow of fluid from the eye. They are less commonly used in dogs due to their potential side effects. Examples include pilocarpine.
It’s important to note that not all dogs with glaucoma respond to medications, and some may require additional treatment such as surgery to manage their condition. Additionally, regular monitoring of IOP is necessary to ensure that the medications are effectively controlling the IOP and preventing further damage to the eye.
Surgical Interventions
There are several surgical interventions that may be used to manage glaucoma in dogs, depending on the severity of the condition and the response to medical treatment.
- Gonioimplant Surgery: This procedure involves the placement of a small silicone tube into the eye to improve the drainage of fluid and reduce intraocular pressure. It is typically used in dogs with advanced glaucoma that are unresponsive to medical treatment. There are a variety of
- Cyclophotocoagulation: This is a laser procedure that is used to reduce the production of fluid inside the eye by destroying part of the ciliary body that produces the fluid. It is typically used in dogs with advanced glaucoma that are unresponsive to medical treatment or are not candidates for gonioimplant surgery.
- Enucleation: This is the surgical removal of the affected eye. It is typically used as a last resort in cases where medical and surgical interventions have been unsuccessful and the eye is causing significant pain or discomfort.
- Evisceration: This procedure involves the removal of the contents of the eye while leaving the outer shell intact. It may be performed in cases where the eye is painful or causing discomfort, but there is still some vision present.
- Partial or Complete Corneal Transplantation: These procedures involve the replacement of the damaged cornea with a healthy cornea from a donor. They may be used in cases where the cornea is damaged due to glaucoma or other underlying conditions.
- Gene Therapy: Experimental procedures using gene therapy to replace faulty genetic material in ADAMTS10 POAG Beagles has shown some promise in limited clinical trials but therapies are likely many years from widespread use.
Long-term Prognosis
The long-term prognosis for dogs with glaucoma depends on several factors, including the underlying cause of the glaucoma, the severity and duration of the condition, the response to treatment, and the presence of any other concurrent medical conditions.
In general, glaucoma is a progressive and potentially blinding disease that can cause irreversible damage to the optic nerve if left untreated or poorly managed. Dogs with secondary glaucoma that are diagnosed early and receive appropriate treatment have a better prognosis than those with advanced or long-standing disease. Dogs with primary glaucoma have a poor prognosis and will likely be blinded by the disease even with the best care and may eventually require bilateral enucleation when pressure becomes uncontrollable by other means.
Regular eye examinations and monitoring of interocular pressure are important in the long-term management of glaucoma in dogs to detect any changes in the condition and adjust the treatment plan as needed. Your veterinarian or a veterinary ophthalmologist can help you develop an appropriate management plan for your dog with glaucoma and provide guidance on long-term prognosis.